Population ecology is the study of how populations — of plants, animals, and other organisms — change over time and space and interact with their environment. Populations are groups of organisms of ...

Immigration was the sole driver of the United States' population growth in a single year for the first time since records began, a new study released Wednesday said. The nonpartisan Migration Policy ...

Birth rates have dropped faster than life expectancy has increased, causing slower population growth around the world. Forecasts from the United Nations predict that world population will actually ...